This invention relates to reconstruction surgery and particularly to reconstruction surgery for a type III acromioclavicular separation of the shoulder. More particularly, the invention relates to the use of a percutaneous coracoclavicular screw to reduce the separation between the clavicle and the coracoid process.
Injuries to the acromioclavicular joint are generally classified as type I-V depending on the type and amount of disruption to the acromioclavicular and the coracoclavicular ligaments. A type III acromioclavicular separation of the shoulder is a common injury that occurs primarily from having a fall to the point of the shoulder. A type III injury is characterized by the disruption of the acromioclavicular and coracoclavicular ligaments, the dislocation of the acromioclavicular joint and the upward relative displacement of the clavicle. The coracoclavicular interspace is greater than the normal shoulder, and the deltoid and trapezius muscles are detached from the distal end of the clavicle.
There are presently three treatment options available. Those options are no treatment, closed reduction, and open reduction.
The first treatment option is to do nothing. With such a passive treatment, a decision is made to accept the deformity. Unfortunately, with such passive treatment, the patient must also accept having pain and fatigue after prolonged physical activity or heavy lifting.
The second treatment option available is the closed reduction. Various closed reduction procedures have been tried in the past using straps, casts, and different taping techniques. It has been generally believed that they would all work if they could be applied continuously. Unfortunately, it has been found they do not work because no one can wear them continuously because of skin breakdown and discomfort. As a result, such treatment regimes have rarely been recommended.
The third treatment option available is the open reduction. The open reduction procedure involves a coracoclavicular repair and repair of the ligaments. This procedure corrects the deformity and is generally accepted to give the best results. However, this entails an extensive open operation. The deltoid and trapezius muscles are taken off the clavicle and dissected to expose the underside of the clavicle and the coracoclavicular ligaments and the coracoid. The procedure requires an in-hospital stay, time for healing of the surgical wound, and rehabilitation. The open reduction procedure was generally recommended as the treatment of choice for people who are going to be doing heavy work or active athletics. The remaining population is generally told to accept the deformity and to accept the pain and fatigue after heavy lifting or activity.
Clearly, the passive treatment and the closed reduction treatment options generally provide unacceptable results. The open reduction treatment, while providing generally good results, has the disadvantage of the in-hospital stay plus the extensive time required for healing and rehabilitation. A surgical outpatient technique that would correct the deformity and allow healing of the injury in a normal anatomic position without extensive tissue dissection and less scarring would provide a substantial improvement over current treatment methods.
According to the present invention, a percutaneous method for surgically reconstructing a shoulder separation comprises inserting metal guide pins into the shoulder to bracket the coracoid process. These pins show up as guides in an image producing means such as an X-ray machine with a TV screen showing the image and the pins. Using the guide pins as a guide for a drill, a first hole is drilled in the clavicle and a generally coaxial second hole is drilled in the coracoid process. A screw is inserted through the first hole in the clavicle, and into the second hole in the coracoid process, and the shoulder separation is reduced by screwing the clavicle to the coracoid process.
In preferred embodiments, the step of inserting the metal guide pins comprises the steps of inserting a first pin over the anterior edge of the clavicle and along the medial edge of the coracoid process. A second pin is inserted over the anterior edge of the clavicle and along the lateral edge of the coracoid process, thereby bracketing the coracoid process. A third guide pin is inserted over the posterior edge of the clavicle and to the middle of the coracoid process. When inserted in this fashion, the first, second, and third guide pins define a triangle. The surgeon then uses the center of the triangle as an entry point for the drill and aligns the drill generally parallel to the guide pins. The drilling step also includes overdrilling the first hole in the clavicle to ensure that the first hole diameter is greater than the generally coaxial second hole diameter.
In other preferred embodiments, a kit is provided for performing the surgical reconstruction of a shoulder separation using means for visualizing the shoulder structure and particularly the clavicle and coracoid process. The kit comprises a plurality of guide pins for insertion into the shoulder, means for drilling a hole through the clavicle and the coracoid process, and means for reducing the separation between the clavicle and the coracoid process. In some preferred embodiments, the means for reducing the separation includes a screw having a head and shank wherein the head is generally spherically shaped and formed to include a hexagonal aperture and a circumferential groove. The reducing means also includes a driver that has collet means for engaging the circumferential groove and a hexagonal tip for engaging the hexagonal aperture. The hexagonal tip and collet cooperate with the hexagonal aperture and circumferential groove to rigidly hold the screw on the driver and provide positive directional control of the screw during the reduction treatment. The kit further includes a washer formed to taper into the shape of the head to make removal easier.
By providing pins for targeting the coracoid process, guiding a drill and a percutaneous coracoclavicular screw, and using a means for visualization to assist in obtaining proper positioning and alignment, the present invention advantageously allows the surgeon to correct the deformity without extensive tissue dissection and with less scaring. Furthermore, it allows healing in the normal anatomic position, eliminates the in-hospital stay, and reduces the time required for healing of the surgical wound, and rehabilitation.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.